The present invention relates generally to a thrombectomy treatment system and method, and more particularly to a percutaneous thrombectomy system and method providing reinfusion of treated blood that is free of blood clots.
Blood clots, such as emboli and thrombi, can pose serious health risks, making treatment and removal of the clots highly desirable. Blood clots may form on the interior surface of a blood vessel and grow in size to occlude the blood vessel at the point of clot formation. Alternately, a portion of the clot may break free forming an embolus capable of occluding a blood vessel anywhere within the vascular system.
When the obstruction occludes a vessel supplying blood to the brain, a stroke may result causing temporary or lasting paralysis of a part of the body or, in severe cases, death. Obstruction of the pulmonary artery or one of its branches can create difficulty in breathing and can potentially cause the patient to die. Blockage of other blood vessels can occur as well causing attendant health concerns. Given the potentially irreversible and destructive nature of such blockage, safe and effective procedures are needed to eliminate clots from the vascular system.
Many factors can contribute to the likelihood of clot formation, including injury to a blood vessel, alterations from normal blood flow, changes in the coagulability of the blood, and formation of fatty plaques on the lining of a blood vessel (atherosclerosis). An abrupt, abnormal change in diameter of a blood vessel wall, such as an aneurysm, increases the potential for blood coagulation. Other factors such as confinement in bed may also result in more sluggish blood flow in the veins and consequent formation of a clot.
Dialysis grafts can disrupt blood flow to an extent that increases the risk of clot formation within the vicinity of the graft junction. Additionally, surface character and compliance mismatch of some graft materials may cause turbulence in the blood flow, which in turn may lead to hemolysis of red cells, provide sites for mural bacterial adhesion and subsequent colonization, and, in areas of blood stasis, promote thrombosis and blood coagulation. Accordingly, dialysis patients are at increased risk for the formation of blood clots in the vicinity of the dialysis graft.
The present invention addresses these concerns by providing a system and a method for removing clots from the vascular system of a patient by withdrawing blood and clots from the patient, filtering the blood to remove the clots, and reinfusing the filtered blood back into the patient.
An apparatus for removal of blood clots from the blood vessel system of a patient is provided whereby clots such as thrombi and/or emboli are extracted from the patient with some of the patient""s blood. As used herein xe2x80x9cblood vessel systemxe2x80x9d includes grafts as well as naturally occurring blood vessels. The blood containing emboli or thrombi is then filtered in a filter unit and collected in a blood collection container. A blood reinfuser communicates with the blood collection container to enable the filtered blood to be reinfused back into the patient. As a result, the reinfusion of filtered blood that is free from blood clots is safely effected.
More specifically, the system comprises a percutaneous catheter assembly, a blood filtration device, a suctioning source, and a reinfuser. The catheter assembly comprises a main catheter for insertion into a selected blood vessel of a patient to permit blood and blood clots to be removed from the patient. The catheter end is positioned at a selected target site to effect removal of a blood clot. The catheter assembly may include a port through which a guidewire, a declotting device such as a thrombolytic device or a balloon, may be inserted to assist in the dislodgement and removal of the blood clot. The end of the catheter may comprise one of various differently configured tips suited to the removal of blood clots. In a selected arrangement, the catheter assembly is in fluid communication with a Y-junction adapter which has one branch in fluid communication with the filtering device to permit the blood to be filtered and a second branch in fluid communication with a waste container to permit disposal of the removed clots.
The main catheter is in fluid communication with a blood filtration device. The filtration device comprises a filter suitable for separating blood clots from the blood and a blood collection device for collecting the filtered blood. The filtration device is in communication with a suctioning source, such as a motorized pump, which provides suction to the main catheter through the filtration device. Application of suction causes blood clots and any accompanying blood from the patient to be withdrawn from the target site through the main catheter and into the filtration device, where the accompanying blood is separated from the blood clots. A reinfuser is in fluid communication with the blood collection device and comprises a delivery device, such as an intravenous (IV) needle and tubing, to reinfuse the filtered blood back into the patient.
In one arrangement, the blood collection device may be separated from the filtration device and attached to the reinfuser for reinfusion of the filtered blood into the patient. In an alternate arrangement, the reinfuser may function to reinfuse the filtered blood to the patient while the blood collection device remains attached to the filtration device.
By the method of the present invention, a catheter is inserted into a graft or a selected blood vessel of a patient and is advanced until the distal end of the catheter is located at a selected target site at a blood clot. Suction is applied to a blood filtration device which is in fluid communication with the proximal end of the catheter. The suction draws the blood clot and any accompanying blood into the distal end of the catheter removing the clot from the patient. The removed blood and blood clot are transported through the catheter into the filtration device where the blood is filtered to separate the clot from the blood. The collected, filtered blood is then reinfused back into the patient through the reinfuser. The filtered blood may be reinfused into the patient while the catheter remains in place. Alternatively, the reinfusion may be effected subsequent to the suctioning to remove the blood clot. Optionally, the reinfusion may be effected through the catheter.
In a selected mode of operation of the current invention, a device, such as a thrombolytic device, is inserted into the catheter and is used to break up the blood clot at the distal end of the catheter prior to removal of the blood clot fragments by suction through the catheter. Optionally, a thrombolytic agent may be introduced through the catheter or systemically to aid in dissolution of the clot prior to removal. In applications where it is not desirable to filter the suctioned clot, the suctioned blood, or a portion of the suctioned blood, may be diverted into a waste container.